“…In the last years, many papers were devoted to the study of some special sequences or special elements, especially in their connections with particular cases of algebras obtained by the Cayley-Dickson (quaternions, octonions). Some of them are: [Ba, Pr; 09], [Ca;16], [Ci,Ip;16], [Fa,Pl;07(1)], [Fa,Pl;07(2)], [Fl;09], [Fl,Sa;15(1)], [Fl,St;09], [Ha,15], [Mo;17], [Si,18].…”